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<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>


    <!-- 引入外部js -->
    <script src="./js/test.js">
        //这里永远都不会执行
        //alert("helloworld")
    </script>


    <script>
        var a = 10 ;
        console.log(a);
    </script>   

</body>
</html>